This twelfth annual report of the administrator of the international transaction log (ITL) provides information to the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol (CMP) on the activities of the ITL administrator for the period from 1 October 2015 to 30 September 2016. This report also contains information on transactions of Kyoto Protocol units, as requested at CMP 6, and information on the outcomes of the 18th Registry System Administrators Forum, which took place on 29 and 30 September 2016 in Bonn, Germany. The CMP, by decision 12/CMP.1, requested the Subsidiary Body for Implementation (SBI) to consider, at its future sessions, the annual reports of the ITL administrator. The SBI may wish to take note of the information contained in this report and to provide guidance to the secretariat and Parties, as necessary, concerning the implementation of registry systems.